The use of topical steroids should stop if the wound gets infected. If the wound stings, rinse it with acetic acid (vinegar) or isopropyl alcohol (this action may reduce the effect of any irritating toxins such as those produced by fire coral). Fire corals are colonial marine cnidarians that when touched can cause burning skin reactions. Nasty rash. Foreign body reactions, which result in granuloma formation, may occur because of retained bits of calcareous material and proteins from injected nematocysts 5. Corals can elicit both toxic and allergic reactions upon contact with the skin. i was stung by fire coral in Egypt, Sharm El Sheikh on both my legs above the knees and on my stomach… this happened at about 1pm, a few minutes after brushing against this coral my legs were burning, it felt like my legs had been slapped hard and i also had the sensation of very painful stabbing pins and needles… on the affected areas my skin had rased lumps. Fire coral often has an orange-brown color with white tips. Fire-coral-related incidents are common among divers with poor buoyancy control. Very painful. Fire coral has encrusted the ladder that divers and swimmers use to exit the water. Scrub with soap and water and then flush with fresh water as soon as possible after contact with the coral. Coral injuries can be complicated with foreign body reactions, localized eczematous reactions, and/or secondary bacterial infections 1.

Doesn't sound like it would be worth the effort even if I found the "fire coral" I'm referring to. You'll still need medical care right after you give yourself the shots, even if your symptoms seem to stop, in order to prevent a delayed reaction. I probably wouldn't be able to achieve the amazing color …

Lasts a long time. It is easy for a foot or ankle that is not protected by neoprene or lycra to brush up against it and cause a severe sting. Swimmers on reefs soon learn to avoid the “fire coral” because of the painful stings it can inflict. Fire coral is fixed to one spot, and with any luck, you won’t go anywhere near it. I can personally attest to the sting. Oozes and scabs over.
Clinical presentations vary depending on whether the reaction is acute, delayed, or chronic. Biology and Identification Fire coral, which belong to the genus Millepora, are found … This fire coral has encrusted a dead coral formation on the reef and takes the general shape of the coral …
Fire coral (Millepora species) and stinging hydroids are sessile organisms that can produce significant envenomation when divers contact these animals with uncovered skin. The good news is that you won’t find it cruising around the ocean like a jellyfish.

Fire coral treatment may also include taking antibiotics, steroid ointments, and anti-itch creams given under medical supervision. Note: The section on brain coral facts contains information and pictures … Fire coral is actually more closely related to jellyfish than coral.